Which of the following should be checked when trailering a machine?

When trailering a machine, the critical factors to consider are the height, weight, and width of the machine, along with the trailer's capacity. This information is essential for ensuring safe transport. Overloading the trailer or exceeding its specified weight capacity can lead to instability while driving and may result in accidents or damage to the equipment and vehicle.

Height and width are also crucial for navigation, especially in areas with low bridges or narrow roads, as exceeding these dimensions can cause serious hazards. Furthermore, knowing the weight helps ensure compliance with road regulations and prevents potential fines or legal issues. Thus, option B encompasses the vital checks necessary for safe and effective trailering of machinery.